WASHINGTON — FBI Director James Comey in a letter to senior lawmakers Friday said the bureau would be reviewing additional emails from Hillary Clinton's private email server "to determine whether they contain classified information," a potentially significant development in the closing days of a presidential campaign that the Democratic nominee had appeared to be putting away.

In the letter explaining his decision to reopen the investigation, Comey said "the FBI cannot yet assess" whether the information is "significant" nor could he offer a timetable for how long it will take investigators to make an assessment.

Comey wrote that the discovery of additional messages had occurred "in connection with an unrelated case," leading to the decision to reopen the probe.

"Hillary Clinton's corruption is on a scale we have never seen before," Trump said, and her "criminal scheme" should not be allowed in the Oval Office.

"Perhaps justice will be done," the GOP nominee said of the development.

In July, Comey announced that while Clinton and her aides while she was secretary of State had been "extremely careless" in the way they'd handled classified information, he recommended that no criminal charges be filed.

Speaking to reporters aboard Air Force One Friday, White House spokesman Eric Schultz said nothing had "surfaced to change the president's opinion and views of Secretary Clinton.''

"He's going to be proud to support her from now until Election Day," Schultz said.

In her press conference Friday, Clinton said she was "confident" whatever is included in the new messages under review "will not change the conclusion reached in July."

Soon after, the director testified before skeptical GOP lawmakers to explain the bureau's recommendation, which had been adopted by Attorney General Loretta Lynch.